e-kayrakli
commented
6 years ago I think the hardest aspect of this issue is what to name the module in which it lives, as I don't think we have an existing module for which it's a good match. We could start a general Iterators module. Or we could start a module designed for helping Python programmers feel comfortable in Chapel (maybe call it Pythonic?). Looking for suggestions here, particularly from the Python-savvy.
- I think the name
`Pythonicis not very pythonic :) - I think it might be off-putting for people who don't know/like python yet still may find this feature useful.
- On a more serious note, an
Iterators(or to follow Python strictly anItertools) module for Chapel could evolve into something with more functionalities specifically geared towards Chapel's domains and distributions. In which case, the namePythonicwill need to be changed, so why not start withItertools:)
There's also a minor question as to what the starting value should be. Python uses 0. Thomas seemed to propose 1 in his feature request based on the .good file. My sense is that since the goal of the iterator is presumably to avoid surprises for Python programmers, we should follow Python's lead here.
I did some grepping to see how I use enumerate and numpy.ndenumerate. Almost always, I used it to pick the index of a list I am iterating. Which made me ask whether that the default start value should conceptually be iterable.start where applicable. For simple arrays, this can easily be achieved in Chapel by for (idx,item) in zip(arr.domain, arr) but I am especially wondering what my intuition be if you pass a tuple to enumerate, as tuples are 1-based.
OTOH, maybe enumerate should be thought of as loop counter iterator, which coincidentally can be used as an index iterator in Python, as Python lists and tuples are 0-based. Anyways, from a more practical standpoint, I think the default value should be 0 initially.
Also see some related PEPs: https://www.python.org/dev/peps/pep-0212/, https://www.python.org/dev/peps/pep-0279/
mppf
bradcray
[capturing a feature request future that @thomasvandoren filed some time ago while working on issue #9222 even though it's a false positive]
To help Python programmers transition to Chapel, this issue proposes supporting an
enumerate()iterator which would behave like Python's while also supporting parallel iteration viaforallloops.Supplying such a function is very straightforward (it's taken me more time to write this issue than to write the serial and standalone versions of it in PR #10328). Furthermore, documenting it would provide an opportunity to teach Python programmers who search for its documentation about zippered iteration in Chapel.
I think the hardest aspect of this issue is what to name the module in which it lives, as I don't think we have an existing module for which it's a good match. We could start a general
Iteratorsmodule. Or we could start a module designed for helping Python programmers feel comfortable in Chapel (maybe call itPythonic?). Looking for suggestions here, particularly from the Python-savvy.There's also a minor question as to what the starting value should be. Python uses 0. Thomas seemed to propose
1in his feature request based on the .good file. My sense is that since the goal of the iterator is presumably to avoid surprises for Python programmers, we should follow Python's lead here.Associated Future Test(s):
test/functions/iterators/thomasvandoren/enumerate.chpl